<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
	String path = request.getContextPath();
	String basePath = request.getScheme() + "://"
			+ request.getServerName() + ":" + request.getServerPort()
			+ path + "/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
	<head>
		<title>Ajax应用</title>
	</head>
	<script type="text/javascript">
  		var xmlHttp;
  		function createHttpRequest(){
  			if(windows.ActiveXObject){
  				xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
  				}
  			else if(windows.XMLHttpRequest){
  				xmlHttp=new XMLHttpRequest();
  				}
  			}
  		function beginCheck(){
  			var xh=document.all.xh.value;
  			if(xh==""){
  			alert("对不起，请输入学号");
  			return;
  			}
  		createHttpRequest();
  		xmlHttp.onreadystatechange=processor;
  		xmlHttp.open("get","CheckUser?xh="+xh);
  		xmlHttp.send(null);
  		}
  		function processor(){
  		var responseContext;
  		if(xmlHttp.readyState==4){
  			if(xmlHttp.status==200){
  				responseContext=xmlHttp.responseText;
  				if(responseContext.indexOf("true")!=-1){
  					alert("恭喜你，该学号有效");
  				}else{
  					alert("对不起，该学号已注册")；
  				}
  			}
  		}
  	}
  	</script>
	<body>
		<form action="">
			学号：
			<input type="text" name="xh" onchange="beginCheck()" />
			口令：
			<input type="password" name="kl" />
			<input type="submit" value="注册" />
		</form>
	</body>
</html>
